1. From the Clinical Pharmacology Unit (C.M.M., A.S., S.S.H., Y., K.M.M.-P., I.B.W.) and Department of Radiology (S.A., A.K.D.), University of Cambridge, Addenbrooke’s Hospital, Cambridge, United Kingdom; and the Departments of Cardiology (B.J.M., M.M., J.R.C.) and Respiratory Medicine (C.E.B.), University of Cardiff, Wales Heart Research Institute, Heath Park, Cardiff, United Kingdom.